Composition and method for marking base materials



Patented Jan. 30, 1945 COMPOSITION AND METHOD FOR BASE MATERIALS MARKING Gustave Rubner, Tuckahoe, N. Y.

No Drawing. Application May 3, 1941, Serial No. 391,770

9 Claims.

This invention relates to a composition and method for marking base materials. It relates particularly to raised, glittering markings on such articles as road signs, billboards, and fabrics.

In the application of raised markings to various base materials such as fabrics, for example, it has been customary heretofore to apply an adhesive composition to the base material that is to be marked or decorated and then to sprinkle or dust thereon reflecting particles. When the adhesive is subsequently set, the fine particles that in falling come to rest on the adhesive adhere to the adhesive at positions of contact with' the adhesive. For many of the particles, this contact is of very restricted extent. As a result, particles project above the adhesive and are readily broken or brushed off as the marked article'is handled or used.

In another method of marking, substantially uniformly colored material is applied, the color being distributed by being soluble in the composition or by undissolved particles that are so small, as in a bronze powder lacquer, as to give a substantially homogeneously appearing product.

The present invention provides a composition and method of applying raised markings in such manner that the reflecting particles are completely embedded in a permanent binder and yet are adapted to sparkle individually. The invention provides also for the application of the raised markings that tand relatively high above the surface of the base material and adhere firmly thereto, with practically no shrinkage in width of the marking as the composition sets. In addition, the invention provides a method of applying the marking in a one-step process, so that it is not necessary to apply a plurality of materials successively to a base.

Briefly stated, the invention comprises a marking composition in gelatinous form including light-reflecting particles, a plastic to serve as a binder for the particles, and a volatile softening medium for the plastic, the composition being adapted to set to non-tacky condition upon evaporation of the softening medium. The invention comprises, also, the method of decorating or otherwise marking a base material by the application of the gelatinous composition described and then causing evaporation of the volatile softening medium. The invention includes, in addition, articles marked or decorated as described and the herein described method of making light-reflecting particles for use as an ingredient of the marking composition.

The gelatinous composition constituting the marking material holds the particles of lightreflecting material in suspension indefinitely, so that there is no tendency to settle. At the same time, the composition is sufliciently soft that it may be applied and preferably is applied to the base material by extrusion through an opening of size adequate to permit passage of the largest particles of light-reflecting material. Thus, the composition is applied to a fabric advantageously by being squeezed manually from a collapsible tube with an outlet of diameter about equal to the width of mark that it is desired to make on the fabric. When the composition is so applied and subsequently set by evaporation of volatile material, there is no substantial shrinkage in width of the strip after application and the said material stands up, in more or less cordlike manner well above the surface of the fabric. For application to a billboard, signs, or the like on a larger scale, mechanical means of forcing the gelatinous material at low pressure through an opening may be used. Thus, there may be provided an orifice in the shape of a slit of width approximately equal to that of the band to be applied to a billboard and of thickness somewhat greater than the desired thickness of the marking material, the extra thickness of the split compensating approximately for the shrinkage in the thickness of the applied band on evaporation of the volatile softening medium. The band is applied fiat to the surface to be marked, in case the slit orifice is used.

The light-reflecting particles that may be used include those that are commonly known by the syncnomous terms tinsel" or tinsel flitter." Among such particles that may be used to advantage are those of silvered glass (a usual form of tinsel flitter) aluminium flakes oi mirror-like surface that are preferably made a described later herein, or other metal flakes of sutiable color and stability in contact with ingredients of the marking composition.

For best results, the particles of light-reflecting material should be of substantial size so that the particles tand out in the raised marking so as to reflect light and sparkle individually. Thus, I have used to advantage particles of reflecting material about 3 2 inch square or of size approximately 20 to 40 mesh, that is, adapted largely to pass through a usual screen having 20 meshe to the linear inch and to be retained on a screen having 40 meshes to the linear inch. If larger particles than this are used, difllculty may arise in passage of a composition containing them through the orifice or opening used in applying my composition to the base material. If, On the other hand, extremely fine particles are used. such as those of the size of particles in common aluminum or bronze powders, then the sparkle or scintillating effect associated with spaced individual particles of flitter is largely lost.

The particles of light-reflecting material before use are incorporated into a gelatinuous composition including a plastic binder that is heatsoftenable or solvent-softenable, suit-ably both. and a volatile softening medium, the softening medium in proportion used being an imperfect solvent and converting the plastic to the form of a gel that is sufiiciently softto be easily extrudable through an opening adapted to permit passage of the largest of the particles of lightrefiecting material but is at least semi-solid, so as to hold the particles of light-reflecting material suspended indefinitely, with no substantial tendency to settle, and to prevent objectionable spreading on the base to which it is applied.

As the plastic in the gelatinous composition, there is used a material that is durable and solvent-softenable, adapted to adhere thoroughly and practically permanently to the base material to which it is to be applied, and transparent and preferably is of color widely different from the color of the surface of the particles of the light-reflecting material. Suitably, the plastic is substantially colorless. so that the composition after application to the base material gives to the eye the appearance of an aggregation of spaced light-reflecting particles supported in a medium that is optically void. If the composition is to be used on a flexible article. such as a fabric, then the plastic used should be one that, by itself or in the plasticized condition in which it may be present, remains permanently fiexible. While the plastic may be thermoplastic. low temperature softening is not desirable when the finished composition is to be used on articles that are subjected to high temperatures for extended periods of time.

Among the plastics that meet the general requirements and that may be used with a great variety of base materials are the following: a polymerized vinyl compound such as vinyl chlora-cetate of resinous consistency. methacrylate resin. and alkyd resins such as glycerine phthalate linoleate. For some purposes there may be used as the plastic binder material pyroxylin. cellulose acetate. or ethyl cellulose in the presence of a plasticizer that is usual in convertin the selected cellulose derivative to plastic form as for example, dibutyl phthalate, tricresyl phosphate, or a sulfonamid that is a non-volatile solvent for the selected derivative. Plasticizers such as those given may be used also as a part of the plastics of the resin type. if it is desired to make the plastic somewhat softer permanently than is the unplasticized resin itself.

In converting the plastic material to gelatinous form. there is used a volatile softenin medium. the medium being used only in such limited amount as to convert the plastic to the form of an extrudable gel that is semi-solid or just sufficiently firm to hold the particles of light-reflecting material in. suspension indefinitely. In the limited proportion used. the softening medium is an imperfect solvent for the lastic. that is, does not form the plastic into a .fluid that pours readily.

Examples of softening media that may be used are the ethyl or methyl ether of ethylene glycol, butyl acetate, ethyl acetate; methyl ethyl ketone. and methyl isobutyl ketone. either alone or mixed with one another: Various proportions of hydrocarbon diluents. such as cleaners naphtha, toluene or xylene. may be incorporated with the softening agents to give a blended softening medium. Likewise there may be used various proportions of ethyl alcohol, butyl alcohol, amyl alcohol, or the like.

The particular softening medium to be used with the selected plastic is chosen from among the known volatile softeners or solvents for the plastic that are of desired softening effect but of imperfect solvent power in the proportion used. Specific examples given later illustrate softening media that may be used with a number of plastics. The media may be pure compound or mixtures, the latter being preferred for many purposes.

In forming the composition to be used in applying raisecl marking to a base material, I have found it advantageous to make first an intimate mixture of the light-reflecting particles with the plastic in powdered or finely divided condition and then to incorporate the softening medium. Thus, tinsel flitter or flake aluminum with mirror-like surfaces is mixed with dry ground Vinylite resin, as in a mixer provided with slow agitation. After the mixture has been made intimate, the volatile solvent is introduced and agitation continued until the whole is formed into a gel.

Various proportions of materials may be used.

The proportion of the reflecting particles to binder will be determined largely by the closeness or distance of average spacing of the particles desired in the finished applied marking. I have used to advantage glass tinsel in the proportion of about one to five parts and flake aluminum in the proportion of about one-half to two for each part of plastic in the gelatinous composition, proportions here and elsewhere herein being expressed as parts by weight. With other flake metal, if used in place of aluminum. the amount is increased over the aluminum about in proportion to the relative densities of the two materials.

The proportion of softening medium to be used is controlled in part by the type of plastic used and in part by the hardness or softness of the gel preferred for a given application of the composition. In typical compositions, I have used to advantage about 1 to 5 parts of the softening medium to l of the plastic. The proportion of the softening medium used will vary also with the activity as a solvent. Thus, there may be formed a gel containing plasticized pyroxylin as the plastic with a relatively large proportion of softening medium, say 5 or more parts to 1 part of pyroxylin, when the medium is one which is of low solvent power.

In case a cellulose derivative is used as the plastic binder, it is desirable to dissolve the selected derivative in an active solvent in the presence of the light-reflecting particles and then to add slowly, with stirring, a precipitating diluent such as toluene, cleaners naphtha, or xylene, until the cellulose derivative is converted to the desired gelatinous form. Thus, toluene is added to a solution of half-second pyroxylin in mixed ester and alcohol solvents until the toluene dilution ratio for the mixed solvents is exceeded and gelling occurs, to form a diiiicultly fiowable mass.

While conventional particles of glass tinsel or the like may be used as the reflecting particles in my compositions, particularly satisfactory results have been obtained with an improved tinsel or tinsel fiitter made as follows: Highly polished aluminum foil of thickness of the order of /1000 of an inch is sheared with a suitable cutting machine, without stamping or otherwise ham- The flake metal or other core material is agi tated with a solution containing the coloring ma-- terial of desired hue, such as a pigment or a fast anillne dye, a normally firm but softenable binder, and a volatile solvent for the binder, the solvent being a solvent for the coloring material also, in case the coloring material is a dye rather than a pigment. The solution is used in about the minimum proportion that, on agitation, is adequate to wet the surface of each of the particles of core material.

Once the particles are wet, then air is passed through the mixer so that the volatile solvent evaporates, the agitation being continued during the evaporation. This evaporation as well as the original mixing of the coloring solution with the core particles is made to advantage at an elevated temperature as for example at about 150 to 200 R, the exact temperature depending upon the binder and solvent used.- After the solvent is largely evaporated, the temperature is allowed to fall gradually, past the temperature of hardening or setting of the binder and to room temperature, agitation being continued during most of this cooling period. As the solvent evaporates and the coating is effected, the binder first thickens, then gradually becomes more or less non-sticky, and finally sets. Since the particles being coated are moved with respect to each other either continuously or at close intervals during the evaporation and setting, the particles do not adhere permanently to each other but-are obtained in discrete form. They break apart as they tumble during the hardening up of the binder to the stage in which it is no longer sticky.

In making the mixture described I have used to advantage as the mixer a tumbler, with solid walls but open ends, that is heated over a low flame during the solvent evaporation stage and finally cooled by air passing through the open ends of the tumbler and over the material in the tumbler.

A suitable binder for the coloring material is shellac or spirit-soluble copal when the softening medium and plastic used in the gelatinous composition are non-solvents for shellac, say. of high hydrocarbon and low oxygen content. The shellac or copal may be applied in solution in wood alcohol or in a mixture of methyl and ethyl alcohols. A resin, such as dammar, as the binder maybe applied in a hydrocarbon solvent when the plastic and softening medium in the gelatinous composition are non-solvents for dammar, say, of a more or less alcoholic nature or high in oxygen content.

A complete marking composition may be made of the following composition:

Parts Vinyl resin, grade VYHH (a copolymer of vinyl chloride and vinyl acetate) 100 Glass tinsel 300 Ethyl lactate as softening medium for the resin 500 In compounding the above formula, the glass tinsel is mixed with the vinyl resin in dry powdered form, then the ethyl lactate is added, and the whole is stirred slowly for about 5 minutes. Rapid stirring is to be avoided because of its effect in thinning the composition.

In another formula. there are used the following materials:

' Parts Vinyl resin, grade VYHH 100 Glass tinsel 120 Methyl and amyl acetate mixed 330 Acetone Metyl cellosolve acetate Dibutyl phthalate 12 The ingredients are compounded as described above, the tinsel being first mixed with the dry powdered resin, the mixed volatile materials constituting the softening medium added. and the whole then stirred slowly until there is produced a soft but shape-retaining gel.

In place of the glass tinsel in the above formulas there may be used aluminum tinsel, say, in the ratio of about 1 part for each part of the resin.

In another embodiment, methacrylate resin or a moderately hard alkyl resin is substituted part for part; for the vinyl resin of the above formula.

In another embodiment, 2 parts of pyroxylin of low viscosity lacquer grade are dissolved in 10 parts of a solvent mixture including butyl acetate 25%, ethyl alcohol 5%, ethyl acetate 5%, and toluene 65%. The solution is then mixed with tinsel flitter, such as glass tinsel or aluminum flakes, and additional toluene is added slowly to the resulting mixture as it is being stirred until the pyroxylin solution just gels into a shape-retaining but extrudable mass.

In making a marking composition including an acrylate resin, the following formula is used:

Parts Propyl methacrylate 100 Troluoil (Petroleum naphtha) Toluol 100 Acetone 10 The particles of tinsel fiitter are preferably mixed in dry form with the methacrylate before it is initially dissolved, the kind of particles used and the proportion to the plastic acrylate resin being as described above in connection with other plastics. In using cellulose nitrate as the plastic, the tinsel fiitter in a typical procedure is mixed with cellulose nitrate in the proportion of 1 to 4 parts for each part of the cellulose nitrate and the cellulose nitrate is then dissolved in a mixture including ethyl acetate and a non-volatile plasticizer for the cellulose nitrate. Toluol is then added to effect precipitation and attendant gelling of the cellulose nitrate. Thus there has been used to advantage a composition of the following formula:

Parts Pyroxylin (10 sec. viscosity) 100 Silvered glass tinsel 200 Dibutyl phthalate 10 Solvent mixture (30% ethyl acetate and 70% toluol) 50 Additional toluol 45 In a similar formula, the pyroxylin used is of viscosity corresponding to the 30-second grade, the toluol as the precipitating material is replaced by xylol, and acetone is added as an addition to the solvent mixture in the proportion of 10 parts for 100 parts of the pyroxylin.

In the application of the material to textiles, the fabric is suitably maintained in stretched or smooth condition and a marking composition of the kind described is squeezed from the opening of a collapsible tube by hand pressure applied to the tube or from other suitable orifice that is moved over and adjacent to the fabric, immediately above positions to which the material is to be applied, so that the gel comes to rest by gravity upon the said positions. Thus, the decoration may be applied to fabric for a gown, waist, or like article. After the composition is applied, the fabric is maintained in stretched or smooth condition and access of air to the applied tinsel composition is permitted, until the volatile softening medium present has evaporated to such an extent that the remaining raised marking is tack-free.

Similar technique is used in marking road signs or billboards, except that relatively wide openings may be used if desired to apply bands of the marking material, the openings being suitably in the form of a slit and the marking material being squeezed through the slit by pressure applied to the composition by mechanical means.

Markings applied as described stand up well above the surface of the base material, adhere thereto, and are substantially free from dusting or brushing off. The particles of light reflecting material, being embedded in a plastic binder, are prevented from oxidation by the atmosphere while at the same time they stand out and sparkle as individuals when exposed to rays of light.

It will be understood that the details iven are for the purpose of illustration and that variations within the spirit of the invention are intended to be included within the scope of the appended claims.

What I claim is:

1. A composition of matter for use in applying raised markings upon a base material, the said composition comprising an extrudable semi-solid gel and particles of tinsel flitter predominantly of size larger than 40-mesh suspended in the gel, the gel including a transparent, water insoluble, normally solid thermoplastic binder and a volatile softening but imperfect solvent medium for the binder material in the proportion present, and the composition setting on evaporation of the volatile softening medium giving a product in which the said particles sparkle individually.

2. A composition as described in claim 1, the plastic being a permanently flexible resin, so

that the composition is adapted, when applied.

to a flexible base and the volatile softening medium evaporated, to give markings that flex with the said base.

3. A composition as described in claim 1, the plastic being a permanently flexible polymerized vinyl acetate compound of resinous consistency so that the composition is adapted, when applied to a flexible base and the volatile softening medium evaporated, to give markings that flex with the said base.

4. A composition as described in claim 1, the said particles being silvered glass and the composition suspending the particles in non-settling manner and protecting the silver from oxidation by the atmosphere.

5. A composition as described in claim 1, the said particles being aluminum flakes, the particles of aluminum flake having highly polished mirror-like unhammered surfaces and being the product of cutting polished aluminum foil, and the composition suspending the particles in nonsettling manner.

6. A composition as described in claim 1, the particles being predominantly of size approximately 20 to 40 mesh and sparkling individually on exposure to light.

'7. A composition of matter as described in claim 1, the gel being transparent and the said particles being of color different from that of the gel, so that the particles glitter individually on exposure to light.

8. In making a composition for applying raised markings to a base material, the method which comprises forming an intimate mixture of transparent, water insoluble, normally solid thermoplastic binder material in powdered form with particles of tinsel flitter predominantly of size larger than 40 mesh and then converting the plastic to gel form by treatment of the mixture with a softening medium for the binder material, the softening medium being used in proportion less than that required to dissolve the binder material completely so as to make the resulting gel so viscous as to hold the said particles in suspension indefinitely and to prevent substantial spreading after application to a base but sufficiently soft to flow under pressure through an. orifice of diameter adequate to permit passage of the largest of the said particles.

9. A composition as described in claim 1, the tinsel flitter being flake aluminum and used in the proportion of one-half to two parts per one part of the binder material.

GUSTAVE RUBNER. 

